Need help with lighting the scene
Maybe try adding a HDRI for your lighting/reflections. Go to the World section of your shading tab and add an Environment Texture (not an Image Texture).
Blender has some HDRI's at ...2.91/datafiles/studiolights/world. You can also find plenty more for free online. One of the most popular places is HDRI Haven (https://hdrihaven.com/hdris/):